Applicant's U.S. Pat. No. 4,021,283, dated May 3, 1977, discloses a method of making aseptic packaging. In accordance with this patent a web of bags is formed which consists of a plurality of interconnected, open-mouth bags having a continuous channel running across and communicating with the open mouths of the bags. The resulting system of interconnected bags and a channel extending across the bags in rendered sterile during the manufacturing process and, since the system is a closed, sealed system, this sterility can be maintained after the web of bags is formed, packaged and shipped to a filling and sealing station. Reference may also be had to Applicant's U.S. Pat. Nos. 3,813,845, dated June 4, 1974 and 3,941,306, dated Mar. 2, 1976.
The web of bags described above is particularly adapted to be used in conjunction with a packaging machine which includes an elongated filling pipe. The filling pipe is inserted in the channel running across the open mouths of the bags, and as the web of bags progresses along the filling pipe, filling material is deposited in the bags, the open mouths of the bags are closed by a relatively wide longitudinally extending heat seal, and the web of bags is separated from the filling pipe by severing the bag material in the area of the longitudinally extending seal closing the bag mouths. In this way, the bags can, in effect, be filled and sealed without exposing the bag interiors to ambient conditions.
However, it will be seen that a possible source of contamination of the sterile bag interiors arises as the filling pipe is initially inserted into the channel at the leading end of the web of bags. Thus, even though the conditions of manufacture are carefully controlled to insure the sterility of the interior of the web of bags, it will be seen that this aseptic condition can easily be destroyed as the web is fed onto the filling pipe of the packaging machine.